The key technology of pre-coating film coating process is mainly the control of film temperature, film pressure and film speed.
Temperature is the primary factor for pre-coating film coating, because the adhesive is hot glue, the temperature determines the melting state of hot glue, and determines the penetration of hot glue molecules into BOP film, ink layer of printed matter, paper, etc. Ability and diffusion ability, although the increase of waist temperature helps to enhance the strength of the stand, but the temperature is too high will cause the film to shrink. The surface of the product is shiny, foaming, and the product is wrinkled. According to practical experience, the film temperature should be Control it between 70~ 100℃.
The surface of the paper is not smooth. Only under the appropriate pressure, the hot melt adhesive in the molten state can completely cover the surface of the printed matter, and the film-coated product can have a bright bonding effect. The pressure is small and the bond is not strong. Pressure is bigger, helps to improve the binding force between film and paper product, however. If the pressure is too high, it is easy to cause wrinkles in the product. And it is easy to damage the surface of the rubber roller, and the deformation reduces the service life of the rubber roller, as the pressure increases. Increase the contact pressure between the rubber roller and the heating flow tube, increase the load on , increase the damage, and increase the load on the transmission system, so too much pressure will affect the service life of the whole machine
In actual production, the pressure should be adjusted according to different papers. For example, for loose paper, the pressure should be higher. Otherwise, the pressure should be lower. According to experience, the lamination pressure is generally set at 8~25MPa.
The speed of lamination determines the melting time of the adhesive on the pre-coating film on the heating roller and the contact time between the film and the paper. The heating time of the adhesive on the BOP film is relatively long when the lamination speed is slow, and the pressure between the film and the paper is relatively long. The bonding time is long and the bonding effect is good, but the production efficiency is low. The lamination speed is fast. The adhesive on the BOP film has a short heating time on the heating roller. The contact time between the film and the paper is short and the bonding effect is poor. The production speed of the film equipment is generally controlled between 5-30m/min. A simple analysis of the three key process technologies in the pre-coating film coating-film temperature , film pressure and film speed, but the three The adjustment and cooperation between the two should be flexibly controlled according to the actual situation of different equipment used, different types of film-coated products, and different types of films used. Only in this way can high-quality film-coated products be obtained.
Special printed matter refers to the printed matter with large printing area, thick ink layer, deep color, high water content and large paper size. Laminate such printed matter
When the coating parameter control is generally as follows
Lamination temperature: 95~115℃
Film pressure: 16-25Mpa
Laminating speed: 5-10m/min